Add Contact not greyed out, causes error in UCP on Internal User Manager Group

When using the built-in, default, internal User Manager Group, the + Add Contact button is available in UCP Contacts.  When pressed, the Add Contact window appears.  Then, when you click Save Changes, the error "unauthorized" is given.

For Internal User Manager Groups, I don't believe Contacts can be added this way at all.  If that is true, the + Add Contact button should probably be greyed out or omitted entirely so that Users don't accidentally try to Add Contacts to that Group, wasting their time and getting confused with the errors.

Thanks,

Dave